Pneumatic-dispatch apparatus



Jan. 5 192s. 1,568,680

J. G. MACLAREN PNEUMATIC DI SPATCH APPARATU 5 Original Filed Feb. 12 1921 Patented Jan. 5, --1926.

UNITE-D STATES PATENT. OFFICE.

JAMES G. MAGL AREN, 0F MAMARONECK, NEW YORK, ASSIGNOR, BY MESNE ASSIGII- MENTS, TO THE LAMSON COMPANY, A CORPORATION OF MASSACHUSETTS.

PNEUMATIC-DISPATCH APPARATUS.

Application filed February 12, 1921, Serial No. 444,592. Renewed July 2, 1925.

To all whom'z't may concern: 7

Be it known that I, JAMES G. MAC'LAREN, a citizen of'the United States, residing at Mamaroneck, in the county of Westohester and State of New York, have invented certain new and useful Improvements in Pneumatic-Dispatch Apparatus, of which the fol-' lowing is a specification.-

This invention relates generally to pneumatic dispatch apparatus. 7

With a view to effecting economy in the use of power, apparatus of this general nature has been heretofore devised for automatically decreasing or wholly nullifying the expenditure of power at the end of a predetermined interval of time, following either the insertion of a carrier into a tube at the beginning of its period of travel or the discharge of the carrier from the tube at the end of its period of travel.,. The first arrangement, that is, the shuttingoif of the expenditure of power at the end of a predetermined period following the insertion of a carrier into a dispatch tube is open to the serious objection that if, for any reason,

a carrier moves more slowly than normal through the tube, the timing mechanism may act to stop the operation beforethe carrier has completed its passage through the tube. In the second case, that is, when the timing mechanism operates at a predetermined interval following the discharge of the carrier from the tube, special mechanism is required to prevent the stoppage of the operation with a following carrier in the tube, and. to stop the operation should it have been started without a carrier being present, in the tube.

In the course of experimentation I have discovered that the objections arising from the use of a timing interval ofpredeter mined extent can be overcomeby conditioning the operation of the automatic stopping means on the amount of power actually being expended in the tube-system during the operation of the motor and not on an arbitrary time interval. The: invention consists in the provision of automatic stopping mechanism which is set into operation by 'the flow of air through the tube follow-ing the starting of the motor and which acts' to quickly bring the motor to rest in'the event that'there is no carrier load in the tube' The effect of placing a load in the tube, silclias the increased resistance to the flow of air through the tube caused by the presence of a carrier in the-tube, is tosuspend the operation of the stopping mechanism and to prevent further progress of the stopping operation, except for periods when the carrier is. descendinga vertical stretch or otherwise ofleringno re-' more comprehensive use and in any situation 1 where the automatic shutting off of power is desirable where one of two, given condi-' tions obtains and where it is desired to interrupt vthe'progress of the stopping operation during any interval in which the other conditlon may be established during the operation of the stopping mechanism.

In the drawing, Figure 1. is a diagrammatic view'of a neumaticdispatch system embodying the lnvention.

Y Figure 2. is an enlarged sectional viewof a motor controlling'device included in the system illustrated in Figure 1. ,y

In Figure 1 of the drawing I a more or less conventionalcform of double vacuum tube'unit in which the tube 1-is open at its reseivlng end 2-to the atmosphere and.

has a discharge terminal at 3. Thereturn tube 4 communicates near'its receiving end 5 with the discharge end 3 of the tube 1, the discharge terminal 6 oftlie return. tube4 communicating at 7 with the exhaust or suctionfpipe 8 leading to theexhausting device 9.. ,The'exhaustingdevicetl is operated by 'anelectric motor 10 which is'arranged to ;be started into operation by. either of the manually operable circuit controllers 11,01 12, ,place'd. respectively adjacent to the carrier-receivingsterminals 2 and 5 of the pneumatic tubes land 4.1: V

While the motor is arranged to be vstarted into operation by manually'operated controlling devices, automatically actuated pneu matic mechanism shown generally .at 13,

have shown Whose operation is initiated by pressure conditions within the tube, operates to cut off the supply of current to the motor, the func- .tioning of the stopping mechanism being interrupt'ed or suspended by the load of a carrier in the tube.

The means under control of the operator for starting the motor 10 to thereby produce a pressure drop in the tube system for propelling a carrier therethrough, includes, in addition to the initiating circuit controllers 11 and 12, a relay 14 of the self-holding type and which serves as a circuit controller for the direct control of the motor 10. The circuit controllers 11 and 12 are connected in parallel to the conductors 15 and 16, the conductor 15 being connected to the terminal 17 of the coil of relay 14, the other terminal 18 of which is connected by way of the conductor 19, post 20, and conductor 21, to the supply conductor The ren'iaining conductor 1.6 of the initiating circuit controlling circuit is connected directly to the other supply main 23, thus providing for the flow of current through the coil of relay 14 when one or other circuit controller 11 or 12 is closed.

The energization of the relay 14 as described, moves the contact armature 24 into engagement with the contact 25, thus closing a circuit from the supply main 22 by way of the conductor 21, conductor 19, post 20, armature 26, contact 27, conductor 28, motor 10, conductor 29, to the return main 23. At the same time a holding circuit is closed through the coil of relay 14 as follows: main 22, conductor 21, conductor" 19, terminal 18, coil of relay 14, terminal 17, conductor 30, contact 31, contact bridging member 32, contact 33, conductor 34, terminal 35, bridging contact member 36, contact 37, conductor 38, and conductor 29 to return main 23. It will thus be seen that a holding circuit is established through the relay 14 which will maintain a closed circuit through the motor 10 until the holding circuit is broken at the contacts 35 and 37 by the operation of the automatically operating stopping mechanism l3.

The stopping mechanism referred to is shown on an enlarged scale in Figure 2 of the drawing. This mechanism includes a cylinder 40 communicating with the exhaust tube 8 of the tube system by way of the restricted port 41, a valve controlled passage 42 and the pipe 43. A pressure responsive device or pneumatic, for example the piston 44 sliding in the cylindrical casing 40, actuates a downwardly projecting stem 45 on which is mounted a stop 46, the stem 45 being slidable through a sleeve 47 on which is mounted the contact member 36 bridging the contacts 35 and 37 already referred to. The arrangement 01? parts is such that the stop 46 will engage the sleeve 47 and lift the sleeve and bridging member 36 out of en gagement with the contact terminals 35 and 37 as the piston 44 approaches the upper limit of its path of travel in the cylinder 40, thereby functioning to break the electrical connections to the motor and to stop the operation of the same.

The condition obtaining in the tube system which will bring about the stopping operation referred to consists in a freedom or unobstruction of flow of air through the tubes, such aswould exist if no carrier were inserted following the operation'of one of the circuit controllers 11 or '12, in response to the action of the exhausting blower 9, and which prevents a rare't'action or lowering of pressure in the tubes sufhcient to cause the lifting of a second pneumatic, for example a piston 48 sliding in the cylindrical casing 56 and loaded with the weight members 49 and carrying the valve 50 for controlling the passage 42. This unobstructed flow of air through the conveyor tubes and through the passageway 42 slowly exhausts air from the cylinder by way of the restricted port 41 whereupon it no carrier be inserted in the tube before the piston 44 completes its full upward range of movement, it breaks, near the end of its travel, the motor circuit at the contacts 35 and 37, to prevent its idle operation when no carrier is in the tube.

The insertion of a carrier in one of the dispatch tubes 1 or 4 has, however, the effect ot'suspending or interrupting he upward movementof the circuit controlling piston 44, since the decreased pressure or partial vacuum thus produced in the tube system acts tobring about the rise of the weighted piston 48 through the rapid exhaustion of air from that portion of the cylinder cham ber above the piston 48, by way of the pipe 8. The piston 48 has attached to it through the rod 52 the valve member 50 which is mounted to reciprocate in the elongate valve chamber formed by the tubular connection 53 between the two cylinders. seen that the rise of the piston 48 carries the valve member 50 into obstructing relation to the passage 42 thus cutting off communication between the exhaust pipe 43 and the lower cylinder to thereby interrupt the upward movement of the piston 44 and the It will be 7 I cylinder 56.

ed port 41; or by the'use of an adjustable valve controlling the port 55 in-the upper Means for resetting the circuit controlling piston 44 takes the form of an electrically controlled valve device 57 having circuit connectionswith the. starting switches 11 and 12 by way of the conductor 58 leading to the supply main 22 and by way of the conductor 59 leading to the conductor 15. By this arrangement the closing of either starting switch will operate to drop the circuit controlling piston to-the circuit closing 7 or" the contact bridging member.

position While the invention has herein been illus' trated and specifically described as embodied in a pneumatic dispatch system having aimotor which is stopped and started to initiate or cutofi carrierpropelling air flow, it is contemplated that the broad un-.

derlying principle of the invention is capable of embodiment in systems of other type, for example so-calledminimum flow systems ,in whichthe flow of carrier propelling air current is determined byopening or closing of a valve. In this event the piston 44 of the-present invention would probably actuate the controlling valve either directly 'or indirectly. As an example ofa minimum flow system-suchas just referred :to. reference may be had to the patentto Libby No. 968,576, August 30,1910.

What I claim is I 7 f 1. In an apparatus'subject to two operating conditions, controlling means including a member responsive to one of the operating. conditions to move toward aposition in 'which the controlling means actsto'stopthe operation of the apparatus,-and a. member responsive to the other operating condition and eflect-ive while-the-second operating condition obtainsto interrupt the movementofv the first-named member. I

2. In a pneumatic apparatus subject in operation to two pressure conditions, control ling means including a member responsive to one of the pressure conditions to move toward a position in which the controlling means acts to stop theoperat-ionof the apparatus, and a member responsive to the other pressure condition and effective while the second operating condition obtains to. interrupt the movement of the first-named.

member. I

3. Power control apparatus for. a pneumatic dispatchsystemhaving a transmission tube and means for creatingcarrier impelling air flow through the tube, said apparatus comprising a pressure. actuated device tending to stop carrier propelling air flow immediatelyafter it is started, and asecond pressure actuated device active so long as a-carrier remains. in the tube to prevent operation of said stop device.

4. A power control apparatus for a pneumaticqdispatchsystem having a transmission tubeand means for creating carrier impelling air flow through the tube,'said apparatus comprising a pressure actuated pneumatic which normally moves slowly in afgiven direction during flight of a carrier through the-transmission tube, means actuable by said pneumatic to stop carrier pro,- pellingair flow when said pneumatic completes its movement in said direction, a sec ond pneumatic sensitively responsive to pressure fluctuationin the tube, and means actuable by the second pneumatic to prevent the first pneumatic from completing its movement in said directon so long as a carrier remains in the tube.

5. In a pneumatic tube dispatch apparatus, a motor for producing a current of air in 'the t-ube'to propel carriers through the tube,

to interrupt the movement of the firstnamed member.

6. In a pressure system subject to two operative pressure conditions, controlling meansfor stopping the operation of the system, said controlling means being arranged to be started into operation by one of said pressureconditions, and means responsive to the othenpressure condition for interrupting the; operation of the controlling means .wlnle the second pressure conditlon exists.

7 Controlling means for a pressure'system subject totwo operativepressure conditions comprising automatic stopping means including a piston responsive to onezof the pressure conditions, means operable by movement of the piston to stop the operation of the system; a piston responsive to the other pressure condition, and means oper able by the second piston to prevent movement of the first piston while the second pressure condition exists. V

-8. Controlling means for a pressure system subject to two operative pressure conditions comprising automatic stopping means including a piston responsive to one of the pressure conditions, means operable by a con siderable movement of the piston tostopthe maintained.

10. Power'control apparatus for a pneumatic dispatch system having a transmission tube and means for creating a carrier impelling air flow through the tube, said apparatus comprising a pressure actuated pneun'iatic which begins to move in a given direction upon introduction of a carrier into the transmission tube, said pneumatic, upon completion of its normal range of movement, causing cessation of the carrier propelling air flow, a second pressure actuated pneumatic moving more rapidly than the first when a carrier is introduced into the tube, and means operable by the second pneumatic to prevent completion of the movement of the first pneumatic in said direction until the carrier has emerged from the tube.

11. Power control apparatus for a pnenmatic dispatch system having a transmission tube and means for creating a carrier im pelling air flow through the tube, said apparatus comprising a pressure actuated pneumatic which tends to move in a given direction while a carrier is in flight through the transmission tube, said pneumatic, I upon completion of its normal range of movement causing cessation of the carrier propelling air flow, and a second pressure actuated pneumatic movable in one direction when a carr er is introduced into the tube and thereby arresting the first pneumatic betore 1t completes its normal range of movement, said second pneumatic moving in the opposite direction when the carrier discharges from the tube.

12. Pneumatic dispatch apparatus having a transmission tube and means for controlling carrier propelling air flow in the tube. said controlling means comprising a pair of pressure actuated elements each normally exposed to the pressure obtaining in the tube. one of said elements responding slowly to a given pressure and the other responding rapidly to a predetermined greater pressure.

13. Power control apparatus for a pneumatic dispatch system having a transmission tube, means for controlling carrier propelling air flow through the tube and means for actuating the controlling means, said actuating means comprising a pair of pressure sensitive pneuinatics, both pneumatics moving in response to a predetermined pressure in the transmission tube,vone of the pneumatics moving more'slowly than the other.

14. Power control apparatus for a pneumatic dispatch system having a transmission tube, means for controlling carrier propelling air flow through the'tube and means for actuating the controlling means, said actuating means comprising a pair of pressure sensitive pneumatics, both pneuinatics normally being exposed to transmission tube pressure and responding to variations 7 1n such pressure, one of the pneumatics moving more slowly than the other, and means actuable by the more rapidly moving pneumatic to interrupt movement of the slower moving pneumatic.

15. Power control apparatus for a pneumatic dispatch system having a transmission tube, means for controlling carrier pro-' pelling air flow through the tube and means for actuating the controlling means, said actuating means comprising a pair of pressure sensitive neumatics, each pneumatic moving in response to a predetermined pressure in the transmission tube, one of said pneumatics moving more rapidly than the other, and a valve aetuable by the more rapidly moving pneumatic to control pressure conditions acting on the more slowly mov-' ing pneumatic.

16. Power control apparatus for a pneumatic dispatch system having a transmission tube, means for controlling carrier propelling air flow through the tube and means for actuating the controlling means, said actuating means comprising apair of pressure sensitive neumatics, said Pneumatics normally being exposed to transmission tube pressure, one of said pneumatics moving more slowly than the other when subjected to a given pressure, and a valve actuable by the more rapidly moving pneumatic to cut oil the less rapidly moving pneumatic from communication with the -transmission tube.

17. Power control apparatus for a pneumatic dispatch system having a transmission tube, means for controlling carrier propelling air flow through the tube and means for actuating the controlling means, said actuating means comprisinga pair of pressure sensitive pneumatics, one pneumatic be ng heavily loaded and the other more lightly loaded, each pneumatic normally being exposed upon one side to transmission tube pressure and at its other side to atmospheric pressure, the more lightly loaded pneumatic communicating with the transmission tube by means of a more restricted passage than the other pneumatic, and a valve actuable by the heavily loaded pneumatic for completely cutting off the lightly loaded pneumatic from the transmission tube pressure.

mass-so 18. Power control apparatus for apneumatic dispatch system having a transmission tube, means for controlling carrier propelling air flow through the tube and means for actuating the controlling means, said actuating means comprising a pair of pressure sensitive Pneumatics, each pneumatic normally being exposed to atmospheric pressure upon one side and to transmission tube pressure upon the opposite side, the movement of one pneumatic to a predetermined extent cutting ofi transmission tube pressure from the other pneumatic.

19. Power control apparatus for a pneu matic dispatch system having a transmission tube, means for controlling carrier propolling air flow through the tube, and means actuating the controlling means, said actuating means comprising a plurality of casings, a pressure responsive element in each casing dividing the casing into two chambers, one of said elements being responsive more rapidly to a given pressure than the other, one chamber of the casing in which the more rapidly responsive element is disposed being connected by a free and unobstructed passage with and one chamber of the other casing normally communicating with the transmission tube by means of a passage of a lesser capacity than the aforesaid passage, the other chambers of said casings normally communicating with the atmosphere.

20. Power control apparatus for a pneumatic dispatch system having a transmission tube, means for controlling carrier propelling air flow through the tube, and means actuating the controlling means, said actuating means comprising a ings, a pressure responsive element in each casing dividing it into two chambers, one chamber of each casing normally communirating by means of a passage with the transmission tube, one passage being more limited in capacity than the other, the other chambers of the casings communicating [reely with the atmosphere, a valve for closing the more restricted of the aforesaid passages, and means connecting said valve with the pressure responsive element in the casing to which the larger passage leads.

21. Power control apparatus for a pneumatic dispatch system having a transmisactuating the controlling which the larger the transmission tube plurality of cas sion tube, means forcontrolling carrier propelling air means,said actuating means comprising a plurality of cylinders, a piston sliding in each cylinder divid ing its cylinder into two chambers, the upper chamber of each casing communicating with the transmission tube by means of a passage, one passage being restricted relatively to the other, a piston valve controlling the restricted passage, and means connecting the iston valve with the piston in that cylin er to passage leads.

22. In a pneumatic tube dispatch apparatus, a motor for producing a partial vacuum in the tube to propel carriers through the tube, motor controlling means including a piston, a 1motor controlling device operated by said piston, a cylinder for said piston normally in communication with the tube, said piston being movable by a drop of pressure in the tube toward a position in which the motor controlling device will stop the operation of the motor, a second piston, a cylinder for said communication with said tube, means controlled by the movement of said second piston to cut ofi communication between the first-named cylinder and the tube, and means restricting movement of the secondnamed piston except under a degree of exhaustion in the tube greater than that needed to operate the first-named piston.

23. In a pneumatic tube dispatch apparatus, a motor for producing a pressure condition in the tube to propel carriers therethrough, motor controlling means includin a piston, a motor stopping device operated pistonbeing in communication through a restricted passage with the penumatic tube and responsive to a pressure condition created therein by the operation of the motor, a second piston, said second piston being also in communication by said piston, said with said pneumatic tube, means controlled by the operation of the second piston to cut off communication of the first piston with the pneumatic tube, restricted from movement except under a pressure condition higher than that required :0 operate the firstnamed piston.

JAMES G.VMAGLAREN.

fiow through the tube, and means second piston also in" said second piston being 

